The epithet “Umm Qashʿam” holds two levels together: the literal danger of a fatal attack and the figurative image of a traveller taking up lodging.
In ḥaythu alqat raḥlahā, ḥaythu is an adverb of place; alqat is a past verb and raḥlahā its object. The whole phrase identifies the place at which death has figuratively settled or has become imminent.